In Australian patent No. 693478 (U.S. Pat. No. 5,869,452) by Monash University, we described the use of a peptide derived from the carboxyl-terminal sequence of human growth hormone, or corresponding regions from growth hormone of other mammalian species, for the control of obesity. This region of growth hormone has the ability to modulate lipid metabolism. In particular, a synthetic peptide corresponding to amino acid residues 177–191 of the human growth hormone sequence (hereinafter referred to as hGH 177–191) was found to reduce body weight gain and adipose tissue mass in a model system for obesity, the C57B1/6J (Ob/Ob) mouse. A subsequent application, PCT/AU98/00724 (U.S. Pat. No. 6,737,407) by Metabolic Pharmaceuticals Ltd, discloses analogues of the hGH177–191 peptide which share this activity. The entire disclosure of U.S. Pat. No. 5,869,452 and (U.S. Pat. No. 6,737,407) are incorporated herein by this reference. All of the studies described in the two earlier specifications were carried out using administration of the peptide by injection.
Our subsequent discovery that these peptides are orally active, possess no known toxicity at any dose, and can be effectively administered at frequencies ranging from once every few days to continuously has led to the concept that, counterintuitively, a fat-reducing food, beverage, or food additive may be produced. In particular, the peptide may be expressed directly by microorganisms which are utilised in production of food products, such as fermentative microorganisms used in the production of beverages such as beer, wine and cider, fermented milk products such as yoghurts and buttermilks, probiotic foods, or fermented meat products such as salami, and baked goods such as breads, including sourdough breads. The peptide may also be expressed in fruit and vegetable plants, such as bananas, tomatoes, or potatoes.
The recognition by the inventors is that the above-mentioned features of the peptides make possible the provision of the growth hormone fragment in a food or beverage product by recombinant DNA methods, thus providing a reliable source of sufficient quantities of the growth hormone fragment in a convenient, inexpensive form for use in various prophylactic and therapeutic applications or in improvement of meat quality, without the necessity for costly purification procedures. In view of the advantageous biological properties of the growth hormone fragment, recombinant organisms expressing the growth hormone fragment are especially useful in a variety of circumstances where it is necessary or desirable to maintain control of weight or of food utilization.